DC/DC converter: ZVS topology
DC/DC converters in automotive applications typically deliver 12VDC to supply the 12V network. The ZVS topology (Zero Voltage Switching) is required to reduce, losses, heating and reliability issues in these converters.A ZVS topology is more suitable for a DC-DC application (400V to 12V) because the output voltage must be adjusted only slightly in the range 10.5V to 15.5V. This enables the global effective turn ratio not to fluctuate significantly.
In these topologies, an input “SHIM inductor” is often needed to achieve the phase-shift function. Premo suggests smart magnetic solutions without any additional SHIM inductor component. The leakage inductance of the transformer can be used to implement the necessary input serial inductance. However, that must be managed carefully because the leakage inductance is a “parasitic” parameter naturally intrinsic in the transformer. This value depends mainly on the winding structure.